• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.78-85
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• 2023

For Multi-UAV systems, a task allocation could be a key factor to determine the capability to perform a task. In this paper, we proposed a task allocation method based on genetic algorithm for minimizing makespan and satisfying various constraints. To obtain the optimal solution of the task allocation problem, a huge calculation effort is necessary. Therefore, a genetic algorithm-based method could be an alternative to get the answer. Many types of UAVs, tasks, and constraints in real worlds are introduced and considered when tasks are assigned. The proposed method can build the task sequence of each UAV and calculate waiting time before beginning tasks related to constraints. After initial task allocation with a genetic algorithm, waiting time is added to satisfy constraints. Multiple numerical simulation results validated the performance of this mission planning method with minimized makespan.

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.113-122
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• 1991

This paper presents the Allocation Priority Scheme (APS) for multiprocessor system. The objective of APS is to reduce the time-complexity on a Physical Mapping Scheme(PMS). The PMS is to allocate the nodes of the Data Dependency Graph (DDG) to the multprocessors efficiently and effectively. The APS provides the priority to each node (vertex) in the DDG. In other words, the goal of the APS is to find a request resource mapping such that the total cost (time-complexity) is minimized. The special case in which all requests have equal priorities and all resoruces have equal precedences, and the comparisons between our APS and other schems are discussed in the paper. The APS provides the heuristic rules which are based on maximum height (MH), number of children nodes ($N_c$), number of father nodes ($N_f$), and computation time ($T_c$). The estimation moth of the computaion time is in the paper.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.223-232
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• 1998

In order to improve the hospital service quality, some hospitals try to reduce the outpatients' waiting time in the hospital. One of the dissatisfied service items at the hospital is the long waiting time to take the prescribed medicine. In most cases, the smaller the number of pharmacists, the longer could be the waiting time. The suggestion of criteria for optimal allocation of appropriate number of pharmacists must be very important to manage the hospital pharmacy. In this paper, we suggest the method to figure out appropriate number of pharmacists through the real situation study at the Sampling Medical Center Pharmacy. We present the simulation study results using the simulation package ARENA and the analysis of statistical distribution of the arriving prescriptions. The result of this research could be applied to the other service business to figure out the optimal allocation of available human resources and to do the job analysis for better service quality.

• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.51-59
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• 2003

Real-Time applications on Grid environment have several problems in terms of resource management addressed as follows; (1) dynamic resource allocation to provide QoS objectives, (2) heterogeneous resources that is different scale, or capacity in same unit, and (3) resource availability, and resource needs. This paper describes the techniques of resource manager (RM) handling above problems to support QoS of dynamic real-time applications on Grid. The contributions of this paper to solve problems are as follows: unification of dynamic resource requirements among heterogeneous hosts, control of resources in heterogeneous environments, and dynamic load balancing/sharing. Our heuristic allocation scheme works not only 257% better than random, 142% better than round robin, and 36.4% better than least load in QoS sensitivity, but also 38.6% better than random, 28.5% better than round robin, and 31.6% better than least load in QoS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.1A
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• pp.34-43
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• 2007

In the IEEE 802.15.3 Medium Access Control (MAC) protocol, Simultaneously Operating Piconets (SOPs) are linked by the parent/child (P/C) or parent/neighbor (P/N) configuration, which work on a Time Division Multiple Access (TDMA) basis. This provides interference mitigation but the overall throughput is limited because the SOPs share the channel time exclusively. The protocol is not efficient for SOPs if we focus on the combination of interference mitigation and high throughput maintenance. In this paper Public Channel Time Allocation (Public CTA) is proposed, which is able to greatly reduce the inter-piconet interference (IPI) and achieve greater throughput without much loss of link success probability (LSP) in the SOPs. The simulation results based on the SOPs of Direct Sequence Ultra Wideband (DS-UWB) system demonstrate that the proposed scheme effectively supports the coexistence of SOPs, and it can not only significantly improve the overall throughput of SOPs but also maintain high LSP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5446-5463
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• 2019

Parallel computing system components should be harmonized, and this harmonization is kept existent using synchronization time. Synchronization time affects the system in two ways. First, if we have too little synchronization time, some tasks face the problem of harmonization, as they need appropriate time to update and synchronize with the system. Second, if we allocate a large amount of time, stall system created. Random allocation of synchronization time for parallel systems slows down not only the booting time of the system but also the execution time of each application involved in the system. This paper presents a simulator used to test and allocate appropriate synchronization time for distributed and parallel heterogeneous systems. The simulator creates the parallel and heterogeneous system to be evaluated, and lets the user vary the synchronization time to optimize the booting time. NS3-cGEM5 simulator in this paper is formed by HLA-RTI federation integration of the two independent architecture and network simulators - NS3 and cGEM5. Therefore, nodes created on these simulators need synchronizations for harmonized system performance. We tested and allocated the appropriate synchronization time for our sample parallel system composed of one x86 server and three ARM clients.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.7
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• pp.639-649
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• 2000

In the relational database systems, the join operation is one of the most time-consuming query operations. Many parallel join algorithms have been developed to reduce the execution time. Multiple hash join algorithm using allocation tree is one of most efficient ones. However, it may have some delay on the processing each node of allocation tree, which is occurred in tuple-probing phase by the difference between one page reading time of outer relation and the processing time of already read one. In this paper, to solve the performance degrading problem by the delay, we develop a join algorithm using the concept of 'synchronization of page execution time' for multiple hash joins. We reduce the processing time of each nodes in the allocation tree and improve the total system performance. In addition, we analyze the performance by building the analytical cost model and verify the validity of it by various performance comparison with previous method.

• Culinary science and hospitality research
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• v.3
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• pp.23-40
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• 1997

This study has been made on the basis of the theoretical model of Beeker's time allocation concerning housewives' advance into society-- a primary cause for enlargint the scope of our food service market and developing the food service industry as a whole. The primary purpose of this study is to clarify the close relationship between housewives' activities in the course of allocating their time and the demand for the food service through Beeker's theory of“Total income and Total price”, analyzing the information obtained through the questionaires sent to the housewives in metropolitan areas. The result of the questionaires shows that the demand of food service is closely related to women's market activities. Yet it has become clear that the demand for food service correlates with housewives' allocation of time in terms of sharing profits. As a result, it is true that the increase in housewives' income per hour has brought about the increase of the term of employment and the decrease in their cooking time, thus greatly increasing the opportunities to dine out. In order words, the increase of housewives' income and the decrease in their cooking time have come to make a great contribution to shortening the time needed to take care of family matters while increasing the demand for eating out, or food service. And it is also clear that the common practice to dine out is derived from the reduction in our domestic duties, indicating the choice of social division of labour, but is needs to be noted that the gradual increase in women's income is sure to have exerted a considerable influence on this practice of eating out.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.859-866
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• 2003

In this paper, we designed the bandwidth allocation scheme with priority consideration for upstream channel access of EthernetPON. The objective of our scheme is to control the multi services in more effective way according to their CoS(Class of Service) or QoS(Quality of Service). The designed scheme considers transmission priority in the both side of OLT and ONU. In the OLT's view, the Two-step scheduling algorithm is applied with which we can support multiple bandwidth allocation policies simultaneously, i.e. SBA for the time-sensitive, constant rate transmission services and DBA for the best-effort services. This Two-step scheduling algorithm reduces the scheduling complexity by separating the process of transmission start time decision from the process of grant generation. In the ONU's view, the proposed scheme controls 8 priority queues of the 802.1d recommended 8 service classes. Higher priority queue is serviced in prior during the allowed GATE time from OLT. The OPNET modeling and simulation result compares the performance of each bandwidth allocation policy with SBA or DBA only approach.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.12-31
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• 2010

The objective of this study is to evaluate the applicability of GIS based multi-directional flow allocation model. In order to evaluate the suggested model in this study, it was applied to real watersheds, Pyeongchang and Soyang river basin. The simulation results were compared with observed values, and showed good agreements. The improvement of accuracy and reduction of simulation time were carried out by applying multi-directional flow allocation. Accordingly, the applied methodologies presented in this study will be used to predict accurate runoff, which plays a major role in integrated flood management. If this model is combined with the techniques of rainfall forecasting, it will contribute to the real-time flood forecasting and warning in the future.